Combined effect of bicarbonate and water in photosynthetic oxygen evolution and carbon neutrality

• 作者: OA Yanyou Wu State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences
• 来源期刊: 地球化学学报(英文）
• 学科: 地球科学
• 年，卷（期）: 2025,（1）
• 页码范围: 77-88
• 页数: 12页
• 语种: 中文

摘要

Carbon neutrality is widely concerned and highly valued by many countries.Biosphere has always maintained the balance between oxidized organic substances and assimilated organic matter,resulting in netzero carbon dioxide（CO2） emissions and maintaining its own carbon neutrality.Nature has set a good example for human beings to coordinate oxygen（O2） balance and CO2balance,and achieve carbon neutrality.How does photosynthetic oxygen evolution initiate carbon and water neutrality?My synthesis shows that photo system Ⅱ functions as carbonic anhydrase to catalyze the reaction of CO2hydration under physiological conditions,and CO2 hydration coupled with chemical equilibrium,H++HCO3-→1/2O2+2e-+2H++CO2,occurs in a photosystem Ⅱ corecomplex.Meanwhile,I focused on the revisiting of four classical heavy oxygen(O18) labeling experiments and found that bicarbonate can promote photo synthetic oxygen evolution,and that photo synthetic oxygen evolution can alternately come from bicarbonate and water,not only water.Bicarbonate photolysis and water photolysis account for half of the photo synthetic oxygen evolution respectively,which can well explain the bicarbonate effect,Dole effect and plants' environmental adaptability.Photosynthetic oxygen evolution initiated the journey of water metabolism and carbon metabolism in nature,which led to the coupling as 1:1（mol/mol） stoichiometric relationship between the reduction of CO2 and oxidation of organic carbon,coordinated the evolution of the atmosphere,hydrosphere,lithosphere and biosphere,and realized "carbon neutrality" in the whole Earth system.